This is about as nightmarish as it must get for snakes: Scientists have finally identified an ebola-related disease that causes snakes to tie themselves into knots, stare off into space, and waste away. The condition, which was first discovered in the 1980s, is called inclusion body disease (IBD), and is known to affect pythons and boa constrictors.

Writing in National Geographic, Ker Than describes how IBD causes bizarre behavioral abnormalities in snakes, including an inability to flip over when turned on their backs, and a condition known as "stargazing," which makes them stare off into space and weave their heads back and forth as if drunk. The virus also makes the snakes more susceptible to other diseases, such as bacterial infections in their mouths.

Snakes infected with the disease also refuse to eat, or regurgitate their food when they do — thus making them starve to death.

Scientists think that IBD causes the buildup of proteins in cells, and that it's transmitted from snake-to-snake. Than explains:

[Mark] Stenglein and his team analyzed the genetic material of snakes infected by IBD at the Steinhart Aquarium in San Francisco during a recent outbreak.

In addition to the known snake genome, they found genetic material belonging to a previously unknown virus.

It appears to be most closely related to a class of viruses known as arenaviruses, that have only been known to infect mammals, namely rodents and people. However, the new virus doesn't fit into the two categories of arenaviruses-New World and Old World-that are currently known.

The snake virus also contains a gene closely related to one found in the Ebola virus, which belongs to a different class known as filoviruses. Ebola, one of the most contagious known viruses, causes death through severe hemorrhaging when it infects humans.

The fact that that the new snake virus contains aspects of two completely different classes could mean that its origins stretch back tens of millions of years.

If that's true, the snake virus is at least 35 million years old, said Stenglein...

Go to National Geographic and read more about this messed-up virus. You can also read the paper at the journal mBio.